package com.cosmo.integration.web;

import java.io.IOException;

import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.AuthState;
import org.apache.http.auth.Credentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.impl.auth.BasicScheme;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;

public class HttpClientPreemptiveAuthenticationInterceptor implements HttpRequestInterceptor {

	// mix from examples and tutorial
	// largely example - http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/httpclient/src/examples/org/apache/http/examples/client/ClientPreemptiveBasicAuthentication.java
	// but avoided setting localContext in factory by specifing BasicScheme here
    public void process(final HttpRequest request, final HttpContext context) throws HttpException, IOException {

        AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);

        // If no auth scheme avaialble yet, try to initialize it preemptively
        if (authState.getAuthScheme() == null) {
            //AuthScheme authScheme = (AuthScheme) context.getAttribute("preemptive-auth");
            CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
            HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
            //if (authScheme != null) {
                Credentials creds = credsProvider.getCredentials(new AuthScope(targetHost.getHostName(), targetHost.getPort()));
                if (creds == null) {
                    throw new HttpException("No credentials for preemptive authentication");
                }
                authState.setAuthScheme(new BasicScheme());
                authState.setCredentials(creds);
            //}
        }

    }

}
